Title of Invention

A METHOD OF MAKING A MEDICAMENT FOR TREATING OR PREVENTING A PROTOZOAL INFECTION IN MAN OR IN ANIMALS

Abstract A method of making a medicament for treating or preventing a protozoal infection in man or in animals, comprising: combining a pharmaceutically acceptable carrier with a sodium salt of a triazine-based anticoccidial agent, wherein the triazine-based anticoccidial agent is selected from the group consisting of clazuril, diclazuril, letrazuril, toltrazuril, toltrazuril sulfone, sulfonotolrazuril, and mixture thereof, in proportios for therapeutic dosage in the man or animal such that a therapeutically effective amount of at least one said sodium salt of a triazine-based anticoccidial agent is less than about 1/2 of therapeutically effective amount of a corresponding non-salt of the triazine-based anticoccidial agent.
Full Text This application claims the benefit of priority in U.S. Provisional
Application Serial Number: 60/103,543, filed on October 8,1998 and in U.S.
Provisional Application Serial Number: 60/112,175, filed on December 14,1998.
HELD OF THE INVENTION
The present invention relates to the treatment and prevention of diseases
caused by protozoan parasites in man and in animals. In particular, the invention
relates to novel compositions and methods for parenteral treatment and prevention
of protozoal disease, e.g., Piroplasmosis, Babesosis, Toxoplasmosis Neospora
Cryptosporidiosis
caninira,(Cryptosporidiosis and Equine Protozoal Myeloencephalitis.
BACKGROUND OF THE INVENTION
Protozoan parasites (also known as apicomplexan parasites) cause a
variety of clinical disease manifestations in both man and animals. For example,
hemoprotozoan parasites of the Babesia genus, namely Babesia caballi and
Babesia equi, are responsible for the economically devastating disease, equine
piroplasmosis. Equine piroplasmosis is widely distributed worldwide although it
is most prevalent in the tropics, sub-tropics and temperate regions (see, Robinson,
Edward N., "Current Therapy In Equine Medicine", Vol.2, pp.299-300, (1987)
(ISBN: 0-7216-1491-4)).
The principal mode of transmission of the protozoan is via a tick vector,
e.g., Dermacentor nitens. Clinical manifestation of acute infection is
characterized by depression, fever, anorexia, icteric mucous membranes,
ecchymotic hemorrhages and edema of the extremities and ventral abdomen.
Death can occur within 24-48 hours and mortality rates in outbreaks may be high
(see, Robinson, Edward, N., "Current Therapy in Equine Medicine", Vol. 3, pp.
499-500 (1992) (ISBN: 0-7216-3475-3)).
Horses which test positive for piroplasmosis (complement fixation or
indirect flourescent antibody tests) are rarely allowed to enter the United States
without first undergoing treatment for the disease or under rigid guidelines (see,
Brooks, L., "Piroplasmosis: The Olympic Question", The Horse, pp. 43-48 (July
1996)). Currently recommended treatment regimens include the use of imidocarb
dipropionate (Burroughs Welcome Co.) and often the treatment produces adverse
side effects which include salivation, restlessness, colic and gastrointestinal tract
hypermotility (see, Kobluk, Calvin N. et al., "The Horse Diseases & Clinical
Management", Vol. 2, pp. 1084-1885 (1995) (ISBN: Vol.2 0-7216-5984-5)).
Moreover, treatment with imidocarb dipropionate has met-with marginal success,
especially when the etiologic agent is Babesia equi (50% to 60%) (see, Reed,
Stephen M. et al., "Equine Internal Medicine", pp. 570-571 (1998) (ISBN: 0-
7216-3524-5)).
Thus, there is a need in the art for an effective anti-protozoal agent and a
method of treatment and prevention of Piroplasmosis which does not produce the
adverse side effects seen with current treatment regimens.
Other examples of blood borne protozoal infection caused by Babesia spp.
include: babesiosis of cattle, e.g., Babesia bigemina and Babesia bovis; caprine
and ovine babesiosis, e.g., Babesia ovis; and canine babesiosis, e.g., Babesia canis
and Babesia gibsoni (see, Smith, Bradford P:, "Large Animal Internal Medicine"
pp.1088-1092 (1990) (ISBN: 0-8016-5062-3)). See also, Bonagura, John D.
"Kirk's Current Veterinary Therapy XII Small Animal Practice", Vol. 12, pp.
315-319, (1995) (ISBN: 0-7216-5188-7)). Likewise, there is a need in the art for
a safe, effective and economical treatment for such infections.
In humans, for example, protozoan infections can cause severe disease
manifestations. A common sequella in patients suffering from acquired immune
defficiency syndrone (AIDS) is Cryptosporidium parvum infection
(Cryptosporidiosis) which produces severe chronic and often fatal diarrhea. The
parasite is found worldwide and lives in cattle and domestic animals and is
excreted in feces. It can be transmitted to humans directly from animals or through
contact with feces, contaminated water or food (see, e.g., "National Institute of
Allergy and Infectious Diseases - AIDS-Related Cryptosporidiosis", www press
release (March, 1991)).
Many attempts have been made to find a threapeutically effective
treatment for this disease. One family of drugs currently used in the veterinary
profession for the treatment of coccidosis, the triazine-based anticoccidial agents
(e.g., tnazmediones ana tnazmeinones) especially diclazuril and letrazuril, have
been tried experimentally in the treatment of dryfosis un man man (see )
National Library of Medicine, AIDSDRUGS Database, DRG-0079 (January 22,
1998); and (National Library of Medicine, AIDSTR1ALS Database, FDA-038B
(April 25,1990)). These compounds are formulated for oral administration and
have met with limited success due to poor absorption. The best response to such
drugs has been seen in persons with the highest blood levels post adminsitration
(see, AIDS Treatment News, No. 111 (September 21,1991)).
To date, however, there is still no efficacious therapy for Cryptosporidial
infections in man (see, Health Canada, Laboratory Centre For Disease Control:
Material Safety Data Sheet - 48, Cryptosporidium parvum, October 11,1997 @
(www.hc-sc.gc.ca/hpb/1cdc/biosafty/msds/msds/48e.html (July 24,1999)).
Accordingly, there still exists an urgent need in the art for a safe and effective
pareneral formulation for the treatment and prevention of potozoal infections such
as cryptosporidiosis or babesiosis.
Equine protozoa] myeloencephalitis (EPM), a central nervous system
diseasd which affects equine species, is also primarily caused by a protozoan
parasite, Sarcocystis neuroma also known as Sarcocystis falcatula. The horse is
not a normal host for this protozoan (the horse is not part of the normal life cycle)
and is considered to be a dead end host. The definitive host is thought to be the
opossum. Equids are infected with the 5. neuroma organisms via ingestion of
food or water contaminated with fees of an infected carnivore such as the
opossum (see, Robinson, Edward N., Current Therapy in Equine Medicine
Fenger, Clara A., "Equine Protozoal Myeloencephalitis", Vol. 4, pp. 329-333
(1997) (ISBN: 0-7216-2633-5)).
Recently, other protozoan parasites have been implicated as also playing
an etiologic role in the pathogenesis of EPM, e.g., Neospora caninum and
Toxoplasma species. Accordingly, there still exists a need in the art for an
effective treatment of EPM which demonstrates broad spectrum efficacy against
all protozoan parasites in the horse inclusive of the aforementioned organisms.
The clinical signs of EPM can vary from case to case. Generally, horses
present neurological signs which are asymmetrical, and actual symptoms will vary
depending upon the severity and location of lesions produced by the parasites in
the brain, brain stem or spinal cord. Ataxia, incoordination and general weakness
are usually present and can be accompanied by muscle atrophy (usually most
notable in the rear limbs). There can be paralysis of the muscles of the eyes and
face, drooping ears, difficulty swallowing (dysphagia) head tilt, altered gait, or
even seizures and collapse. Recent reports of numbers of EPM cases indicate that
the disease is far more widespread and serious than originally thought.
There is currently no vaccine available for prevention of this disease.
Previously preferred treatment was aimed at control of the parasitic infection via
the use of sulphonamides and pyrimethamine (see, U.S. Patent No.: 5,747,476).
However, these measures have been met with limited success. More recently, and
due to the urgent need for a safe and effective treatment for this devastating
disease, new methods of therapy and new agents have been explored, e.g.,
through the emergency FDA importation of anticoccidial agents such as diclazuril
and toltrazuril (see, FDACVM publication: "Instructions for Personal Use
Importation of Diclazuril" (December 16, 1997); and FDACVM publication: "The
Importation of Toltrazuril for Personal Use" (1997) which are available from the
American Association of Equine Practitioners, Lexington, KY (AAEP)). (See
also, U.S. Patent No.: 5,883,095).
It should be noted that the current emergency importation and treatment of
horses with diclazuril and toltrazuril is speculative. Oral formulations adapted for
use in the horse of one or more of these drugs are currently in clinical trials for
FDA approval. And, while some horses do dramatically improve, many only see
moderate improvement (improve 1-2 grades on the clinical evaluation scale
(ranging in grades of 1-5) used by veterinarians to classify the severity of clinical
signs). The test dose for a presently preferred form of toltrazuril. the metabolite
toltrazuril sulfone (Bayer) is currently 5 mg/kg up to 10 mg/kg per day for the
FDA trials.
The cost for importation and use of the above anticoccidials ranges
anywhere from about $800-$ 1,200.00 per horse and results obtained from the
treatment can be disheartening. Few horses experience complete recovery from
any known conventional therapy, including the triazine-based anticoccidial
therapies which are mentioned above. Moreover, the relatively high levels of drug
recommended in the therapeutic regimen can produce unwanted side effects. This
is especially true for treatment regimens which utilize sulfonamides and
pyrimethamine which inhibit folic acid production (see, Fenger, Clara A., "Update
on the Diagnosis of Equine Protozoal Myeloencephalitis (EPM)" Proc. 13th
ACVIM Forum, pp.597-600 (1995); and Bertone, Joseph J., "Update On Equine
Protozoal Myeloencephalitis", FDA Veterinarian, Vol. XI, No. HI (May/June
1996)).
Therefore, there exists a need in the art to provide a safe and more
effective method of parenteral treatment of EPM which is also less costly.
SUMMARY OF THE INVENTION
The present invention satisfies the need in the art by providing a
composition containing at least one anti-protozoal drug especially adapted for
parenteral administration, e.g. intranasal intramuscular, subcutaneous,
transdermal or intraveneous administration, for the treatment and prevention of
protozoan infections in man an in animals. In one embodiment, the anti-protozoal
drug is a triazine-based anticoccidial agent, e.g., a triazinedione or triazinetrione
such as diclazuril or toltrazuril. In a presently preferred embodiment, the triazine-
based anticoccidial agent is sulfonotoltrazuril.
The compositions of the invention can further comprise a suitable solvent
for the anti-protozoal drug in a formulation specially adapted for a particular route
of parenteral administration. The choice of solvent and concentration of active
ingredient dissolved therein will of course vary depending upon the choice of
drug, the desired route of parenteral administration, the species and host being
treated, and the desired duration of action of the administration, e.g., sustained
release vs. loading dose.
Parenteral administration of the compositions of the invention reduces the
dosage amount of drug by about one fold to as much as one hundred fold but
especially about five fold compared with oral dosing. The compositions provided
by the invention eliminate the variability in plasma concentrations of the drug due
to animal to animal differences in oral bioavailabilty, allow use of a loading dose
and therefore immediate attainment of effective plasma concentrations of the
drug, allow rapid attainment of high plasma concentration of the drug to drive the
drug into extravascular compartments such as the cerebrospinal fluid in the CNS,
provide better and more immediate control of the plasma concentration of the
drug and reduce the potential for side effects related to the currently existing oral
formulations. As a result, the cost of treatment is greatly reduced along with the
potential for adverse side effects as seen from higher doses currently
recommended and needed for oral administration of these anti-protozoal drugs.
In particular, the present invention provided novel compositions and
methods for the treatment and/or prevention of any anti-protozoal or
apicomplexan parasite in man and animals, e.g., equine piroplasmosis, equine
protozoal myeloencephalitis and Cryptosporidiosis. In one embodiment, the
invention provides a composition comprised of triazine-based anticoccidial drug
and a suitable solvent useful for the treatment of anti-protozoal infections. A
preferred embodiment of the invention comprises a composition comprised of
diclazuril in solution with dimethylsulfoxide (OMSO), dimethylamine (DMA) for
mixtures thereof which is formulated for parenteral administration for the
treatment of anti-protozoal infection in man or in animals as provided by the
methods of the invention.
Another preferred embodiment of the invention comprises a composition
comprised of toltrazuril, toltrazuril sulfone, sulfonotoltrazuril or mixtures thereof
in solution with DMSO, DMA or mixtures thereof which is formulated for
parenteral administration for the treatment of anti-protozoa! infection in man or in
animals as provided by the methods of the invention.
Yet another preferred embodiment of the invention comprises a
composition formulated for parenteral or oral administration for treatment of anti-
protozoal infections in man and in animals comprised of a soluble salt, e.g., a
sodium salt, of a triazine-based anticoccidial agent, e.g., clazuril, diclazuril,
letrazuril, toltrazuril, toltrazuril sulfone, or sulfonotoltrazuril and the like.
Also provided by the invention is a method for preparation of water-
soluble forms of triazine-based anticoccidial agents, e.g., clazuril, diclazuril,
letrazuril, toltrazuril, toltrazuril sulfone, or sulfonotoltrazuril for use in the
methods of treatment of anti-protozoal infections provided by the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a composition and method for the
parenteral treatment of protozoan (apicoplexan) infections in man and in animals.
The protozoan parasite can be any protozoan known to infect man or animals,
including, but not limited to, e.g., Babesia spp. Sarcocystis spp. Neosponim spp.
Crytosporidium spp. Toxoplasma spp. and the like.
It is contemplated that the compositions of the invention can be formulated
for any parenteral administration. It is specifically contemplated that intravenous,
intramuscular, transdermal, intranasal and subcutaneous routes of administration
can be utilized for administration of the compositions of the invention. Specific
formulations of the compositions of the invention can include powders, gels,
ointments, creams, solutions, suspensions, sustained release preparations, patches
and the like.
In one embodiment, the invention provides a composition specially
adapted for intravenous, intramuscular, subcutaneous, or intranasal administration
which is useful for the treatment of a protozoal infection in man or in animals,
e.g., for treatment of equine piroplasmosis, equine protozoal myeloencephalitis or
human cyrptosporidiosis infection, wherein the composition comprises at least one
chemical agent which has anti-protozoa1 activity. The compositions provided
herein can include any anti-protozoal agent, but especially anti-coccidial agents
such as any of the class of triazine-based anti-coccidial agents (i.e., agents which
contain a triazine ring, e.g., the 1,2,4 triazine ring or the 1, 3, 5 triazine ring
configurations (see, e.g. "A 3D-QSAR Study of Anticoccidial Triazines Using
Molecular Shape Analysis", J. Chem. Inf. Comput. Sci., Vol. 35, 771-778 (1995);
U.S. Patent No. 4,837,216; and U.S. Patent No. 4,952,570, the contents of which
are incorporated herein by reference).
Specific examples of such agents include, but are not limited to, clazuril,
diclazuril, toltrazuril, toltrazuril sulfone, or sulfonotoltrazuril. For example, the
chemical structures of several triazine-based compounds useful in the
compositions and methods set forth herein are shown below:
It can be appreciated that other anti-protozoal agents including their
derivatives, analogs, isomers, salts, and natural metabolites of these agents can
also be utilized in the compositions for parenteral treatment and prevention of any
protozoal infection in man or in animals. In a presently preferred embodiment,
the triazine-based anticoccidial agent is sulfonotoltrazuril, a toltrazuril metabolite.
Sufonotoltrazuril, the toltrazuril metabolite, contains the thio group of
toltrazuril that has been oxidized to a sulfono group thereby differing toltrazuril
from its dioxo sulfonotoltrazuril derivative.
The chemical name used in the Chemical Abstract Database for one form
of the sulfonotoltrazuril contemplated by the invention is:
l-methyl-3-[3-methyl-4-(4-trifluoromethanesulfonyl-phenoxy)-phenyl]-
[ 1,3,5]triazinane-2,4,6-trione.
The CAS catalog number of this compound is CAS No. 69004-04-2. The
Beilstein Registry Number is 870959. The Molecular Formula is C18H14F3N3O6S
and the Molecular Mass is 457.38 g/mol.
In particular, the invention provides a composition which is useful for
parenteral treatment and/or prevention of EPM which utilizes between about l/4th
to about 1/100th of the amount of an anti-protozoal drug which is necessary for
oral administration in the treatment of EPM. In one embodiment of the invention,
the compositions are adapted for intranasal administration and comprise about
1/1 Oth of the currently recommended dosage. In another embodiment, the
compositions are adapted for other parenteral administration (e.g., intravenous,
subcutaneous and intramuscular) and comprise between about l/4th to about
1/100th of the currently recommended oral dosage, but especially about 1/3rd to
about l/10th of the currently recommended oral dosage for EPM treatment. In a
preferred embodiment, the intranasal and parenteral compositions of the invention
set forth above are formulated for sustained release as set forth in greater detail
below.
For example, the currently recommended dosage for oral diclazuril
(CLINACOX®, Pharmacea Upjohn, Canada) in the horse for an EPM treatment
regimen is about 2.5 grams of diclazuril per 1000 pound horse per day (5.5 mg/kg)
administered once daily for 28 days. This amounts to about 70 grams of diclazuril
per horse per treatment regimen.
By contrast, the presently preferred dosage range for the parenteral
compositions of the present invention for treatment of EPM which are comprised
of similar triazine-based agents, e.g., diclazuril or toltrazuril and the like, is from
between about 0.1 mg/kg to about 10 mg/kg. However, the skilled artisan can
appreciate that this range can vary from between about 0.01 mg/kg to about
20mg/kg depending upon the specific formulation, route of administration, the
desired effect (loading dose vs. sustained release) and the duration of the
treatment regimen.
A presently preferred embodiment of the invention comprises a
composition adapted for parenteral administration wherein the anti-protozoal
agent is selected from, but not limited to the group consisting of clazuril,
diclazuril, letrazuril, toltrazuril, toltrazuril sulfone, and sulfonotoltrazuril or a
sodium salt thereof and a suitable solvent. The solvent can be any suitable solvent
for use in animals and man and will, of course vary depending upon the choice of
anti-protozoal agent and the route of administration. Presently preferred solvents
include, but are not limited to DMSO, DMA, ethanol, water and the like as set
forth more fully below.
The preferred compositions can be utilized in methods of treatment of anti-
protozoal infections in man and in animals. For example, a presently preferred
treatment regimen for treatment of EPM comprises administering to a 1000 1b
horse a composition for intravenous administration comprised of between about
50 mg to about 1,500 mg, but especially between about 250 mg and about 1000
mg and most preferably about 500 mg (about 1.1 mg/kg) of diclazuril, toltrazuril,
toltrazuril sulfone or sulfonotoltrazuril dissolved in a suitable volume of DMSO,
DMA or the like. Suitable amounts of solvent will vary from between about 2 ml
to about 30 ml per unit dose depending upon the choice of the anti-protozoal agent
and the choice of solvent. According to the methods set forth herein, the
composition can given once per day (SID) for a duration of between about 10 and
about 35 days but especially between about 20 and about 30 days and most
preferably about 28 days. Alternatively, a loading dose of the composition can be
given to achieve rapid critical plasma concentrations on day one of the regimen
followed by a maintenance dose (see, Example 1 below) for a shorter duration of
therapy, e.g.. between about 15 and about 25 days.
In yet another embodiment, the compositions can be specially formulated
for parenteral use, e.g., intramuscular or subcutaneous, sustained release, e.g., a
microsphere or methylcellulose preparation such that a single sustained release
administration or a weekly administration of sustained a sustained release
formulation of the anti-protozoal agent is possible. Alternatively, a single
intraveneous loading dose followed by a sustained release intramuscular or
subcutaneous dose for maintaining sustained critical blood levels is contemplated.
In EPM, for example, the critical plasma concentration can range from about 5
mg/ml of the antiprotozoal agent to about 12 mg/ml, but especially about 8 mg/ml.
INTRAVENEOUS ADMINISTRATION EXAMPLES
EXAMPLE #1
"MR. OWENS" AND SINGLE IV ADMINISTRATION OF DICLAZURIL:
DAYS POST DOSING ?
As set forth in Table 1 above, the horse MR. OWENS, (about l,000 lbs.) received
750 mg of diclazuril powder dissolved in 30 ml of DMSO, intravenously, twice on
day one, at zero and zero plus one hours for a total dose of 1,500 mg. Blood
samples were drawn at the indicated time points immediately before the next
dosing and the solid circles (•—•) in Fig 1 represent plasma concentrations of
diclazuril after these administrations. Plasma concentrations of dicalzuril in ng/ml
are represented on the vertical axis against time in days on the horizontal axis.
Note the 6,000 ng/ml of diclazuril peak blood level at 24 hours after dosing, and
the approximately 48 hour plasma half-life, consistent with previously reported
data on the plasma half-hfe of dicalzuril in the horse.
EXAMPLE #2
"DEEP POWDER" AND REPEATED DAILY IV ADMINISTRATION OF
DICLAZUR1L: -
The horse, DEEP POWDER, 1160 lbs., in Table 2 above was administered
diclazuril at a dose of 0.5 mg/lb. (580 mg) in DMSO IV once a day for eight days.
Plasma levels of diclazuril at 24 hours after each dose administration and just
before the next day's dosing are represented by the solid circles (•—•) in the
above Table 2. Note how the dose of 580 mg/l,0001bs/day yields a stepwise
increasing plasma concentrations of diclazuril, yielding a final steady state plasma
concentration of diclazurii of about 10,000 ng/ml. Note also the close comparison
between these data and data previously presented on CLINICOX®, where daily
oral administration of about 2.5 g / 1,000 lbs. of diclazurii as CLINICOX®
yielded broadly similar data. The data show that IV administration of about 0.5
mg / 1, 000 lbs. of dicalzuril in DMSO produced equivalent plasma concentrations
of diclazurii as about five times this dose of CLINICOX®orally, suggesting about
20% or less oral bioavailability of this agent.
EXAMPLE #3
"LOADING DOSE" EFFECT AND EXPECTED THERAPEUTIC BENEFITS:
DAYS POST DOSING ?
Pharmacokinetics and the summation principle teaches us that administration of a
loading dose such as that presented in Example 1, MR OWENS, followed by a
daily maintenance dose such as that presented in Example 2, DEEP POWDER,
should allow rapid attainment and maintenance of a desired or therapeutically
optimal plasma concentration of (about 8-10 ug/ml in plasma) diclazuril. Table 3
above shows the estimated plasma levels that would be obtained in horses of the
approximately 1,000 lb. body weights of MR. OWENS and DEEP POWDER if
the 1,500 mg loading dose was administered on day I, followed by daily
maintenance doses of 500 mg day as was administered to DEEP POWDER. In
this way, and following these general protocols and principles, it would be
possible to rapidly attain full effective plasma concentrations of dicalzuril or a
related agent on day one of treatment and maintain these effective concentrations
for any desired period of time.
The advantages of this approach are many fold: In the first place, effective
plasma and cerebrospinal fluid concentrations of dicalzuril or a similar agent are
attained within hours or minutes of the start of treatment, which can lead to
shorter treatment periods. In the second place,-the required plasma concentrations
can be maintained by the administration of only about one fifth or less of the total
drug amount that must be administered orally, based on our experience with
CL1NICOX® administration, which may lead to substantial savings on drug costs.
Thirdly, the significant horse to horse variability in bioavailability of this agent
and the resulting variability in plasma concentrations of diclazuril found after oral
administration can be avoided, leading to more predicable and reproducible
treatment results. Fourthly, using this methodology, very high plasma
concentrations of diclazuril can be rapidly attained, leading to equivalently rapid
entry of diclazuril into the CNS and to equivalently rapid anti-protozoal actions in
the CNS. Fifthly, the optimal plasma concentrations of dicalzuril to treat this
disease and the optimal duration of therapy and most cost effective therapeutic
approaches to EPM have yet to be conclusively established.
This IV approach to administration of diclazuril, by allowing precise
control of drug concentrations and rapid entry of drug into the CNS, provides a
tool necessary to precisely control the plasma levels of the drug and cerebrospinal
fluid concentrations of this agent to obtain this information. Sixth and finally, the
fact that IV administration exposes the horse to less of this drug and to none by
the direct intestinal route reduces the probability of adverse effects developing
relating to the gastrointestinal system and also to other body systems of the horse.
EXAMPLE # 4
MR. OWENS / CLINACOX DATA: PHARMACOKINETIC ANALYSIS AND
BIOAVAILABIL1TY CALCULATIONS:
Pharmacokintetic analysis of the data obtained after IV administration of this drug
and comparison with previously reported pharmacokinetic data after
administration of CLIN1C0X® (Table 4 above) shows that the estimated oral
bioavailability of CLIN1C0X® may be actually less than the earlier estimated
20%. In Table 2, the intravenous data from MR. OWENS (solid squares ¦—¦) is
plotted along with the previously obtained CLINICOX®oral administration data
(solid circles •—•) and subjected to pharmacokinetic analysis as set forth below.
These data suggest that the bioavailability of orally administered CLINICOX®is
about 13 % less that the figure developed in the experiments presented above.
EXAMPLE # 4:
MR. OWENS / CLINACOX DATA: PHARMACOKINETIC ANALYSIS AND
BIOAVAILABILITY CALCULATIONS / CONTINUED:
Following oral administration, concentration of diclazuril at 120
hours was considered as outliers.
Area Under the Curve (AUC fiom 0 to ): Trapezoidal rule was
used to calculate area under the curve for oral drug administration.

First order process: k= LnC1-LnC2_____k=0.0164 hr"1
tl-t2
AUC from 0 to °° (PO)= 98.2 ng/ml/hr
Concentrations at 72 hr and 96 hr were not included in calculation
following IV administration.
Area Under the Curve (AUC from 0 to ): Intercept-Slope Method

AUC (AUC from 0 to ~) (IV): 452.4 ng/ml/hr
Not detectable level of diclazuril in urine samples by both HPLC and TLC
methods suggested that hepatic clearance is the major elimination route for
diclazuril in horses.
ClH = Qh- Eh
EH is lower than 0.3 so diclazuril is found to have low hepatic extraction
ratio.
In yet another embodiment of the invention, the above-described preferred
compositions can be utilized in methods of treatment of anti-protozoal infections
in animals other than EPM. For example, a presently preferred treatment regimen
for treatment of Piroplasmosis in horses comprises administering to a 1000 1b
horse a composition for intravenous administration comprised of between about
50 mg to about 1,500 mg, but especially between about 2S0 mg and about 1000
mg and most preferably about 500 mg (about 1.1 mg/kg) of diclazuril, toltrazuril.,
toltrazuril sulfone or sulfonotoltrazuril dissolved in a suitable volume of DMSO,
DMA or the like. Suitable amounts of solvent will vary from between about 2 ml
to about 30 ml per unit dose depending upon the choice of the anti-protozoal agent
and the choice of solvent. According to the methods set forth herein, the
composition can given once per day (SID) for a duration of between about 1 and
about 20 days but especially between about 1 and about 10 days and most
preferably about 4 days. Alternatively, a loading dose of the composition can be
given to achieve rapid critical plasma concentrations on day one of the regimen
followed by a maintenance dose for a shorter duration of therapy, e.g., between
about 2 and about 10 days. In yet another embodiment, the compositions can be
specially formulated for sustained release as set forth below such that a single
administration of the anti-protozoal agent is possible or, alternatively a single
intraveneous loading dose followed by an intramuscular or subcutaneous dose for
sustained critical blood levels.
As set forth above, clazuril, diclazuril, toltrazuril, toltrazuril sulfone and
sulfonotoltrazuril as well as other triazine-based anti-coccidiais agents that are
useful in the prophylaxis and therapy of equine protozoan myeloencephalitis
(EPM) and other protozoal diseases in man and animals. These compounds are
hydrophobic and highly water insoluble.
Prior to the teachings set forth herein, there had been no suitable water
soluble formulation for parenteral administration of these agents. Accordingly,
the present invention provides compositions comprised of a water-soluble form of
at least one anti-protozoal agent which is useful for the treatment of a protozoal
infection in man or in animals and a method for making such a composition. In a
presently preferred embodiment, the composition is comprised of the sodium salt
of one or more triazine-based anticoccidial agents, including, but not limited to
clazuril, diclazuril, letrazuril, toltrazuril, toltrazuril sulfone, sulfonotoltrazuril or
mixtures thereof.
A presently preferred way to increase the water solubility of such drugs is
to make their salt forms. Clazuril, diclazuril, toltrazuril, toltrazuril sulphone and
sulfonotoltrazuril are weak acids because of the imide hydrogen present in all five
compounds as shown below. The anion formed when this hydrogen gets
abstracted is resonance stabilized. Thus, these acidic compounds can be reacted
with a base to form the corresponding salt and water in a typical acid-base titration
reaction. For instance, the sodium salt of diclazuril was formed by reacting
diclazuril with sodium hydroxide as set forth below in a 1:1 molar ratio.
Synthesis of the sodium salt of diclazuril.
Evidence for salt formation:
1. Molar ratio of sodium hydroxide required for compete titration of diclazuril
was 1:1.
2. The salt dissolves immediately in water while diclazuril is completely insoluble
in water.
3. Diclazuril is a white powder. The sodium salt of diclazuril has a brownish tan
color.
4. Mass spectral analysis in the negative mode of the sodium salt of diclazuril
and diclazuril itself was conducted. The expected molecular weight of the
molecular anion of the salt and the parent compound is 404.971. The measured
molecular weight matched exactly to the expected weight (Data not shown).
Therefore, clazuril, diclazuril, toltrazuril, toltrazuril sulphone, and
sulfonotoltrazuril, as well as certain other triazine-based anticoccidials, have in
common an acidic imide hydrogen which allows for an acid-base titration reaction
with a base to give the corresponding salts and water. This was demonstrated with
the synthesis of the sodium salt diclazuril as set forth more fully in Example 5
below. Give the teachings provided herein. it can be appreciated that other alkali
bases including, but not limited to Ca(OH)2, KOH, LiOH can also be used
EXAMPLE 5
Synthesis of a water-soluble salt of Diclazuril
Diclazuril has a very low solubility in water ( in fact be considered as practically insoluble in water. A presently preferred
plasma drug concentration of about 8mg/ml for about 25-30 days is needed for the
effective treatment of equine protozoan myeloencephalitis (EPM). The oral
bioavailability of diclazuril is very low. Thus, a parenteral formulation is desired.
One of the methods to increase the water solubility of poorly water-soluble
drugs is to make water-soluble salts of the drug. Diclazuril can be considered as a
weak acid because of the presence of the imide hydrogen as shown below:
Structure of diclazuril with arrow indicating the acidic imide
hydrogen.
The anion formed when this acidic hydrogen gets abstracted is stabilized
by resonance below:
Resonance structure of chclazuril made anion
Since diclazuril is a weak acid, it can react with a base to give a salt and
water. NaOH was chosen as the presently preferred base and an acid-base reaction
was carried out wherein 1 gram of diclazuril was suspended in 50 ml of ethanol in
a 200 ml volumetric flask. To this, phenolphthalein indicator was added to
indicate equivalence point of titration A buret was filled with 1M NaOH. The
base was slowly added from the buret to the solution. The titration was stopped
when a change in the color of the phenolphthalein indicator (colorless to pink)
was observed. At the equivalence point, it was observed that the white milky
suspension of diclazuril had changed to a clear pink solution. This was thought to
be due to the conversion of the acid to the salt. The solution was re-crystalized by
evaporation in an oven set at 75°C for two hours.
Synthesis of sodium salt of diclazunl.
Calculation of moles of NaOH required to titrate 1 mole of diclazuril indicated
that the molar ratio was 1:1, suggesting acid-base reaction and thus salt formation.
While it is possibe that the nitrile and imide functional groups can be
hydrolyzed by a base. This probably does not occur, however, because hydrolysis
of nitrites and imides requires more severe conditions including refluxing for
several hours. In addition, the reaction was conducted in ethanol thereby
eliminating water required for the hydrolysis reaction.
Evidence for salt formation
1. The titration experiment strongly suggests acid-base reaction.
2. Mass spectral evidence Fourier transform matrix-assisted laser desorption
ionization mass spectrometry (MALD1-FTMS) with dithranol matrix was used
to measure the mass spectra of diclazuril starting material and diclazuril free
acid obtained from the sodium salt of diclazuril. The expected molecular
weight of diclazuril anion (CI7 H8 C13 N4 o2-) is 404.972. The measured
molecular weight is 404.971. Isotopic peaks arising from chlorine were
measured at m/z of 406.967 and 408.965. A cluster of peaks at molecular
weight 333.971 in the spectrum corresponds to a fragment peak of the
molecular ion formed after the loss of two chlorine atoms. The sodium salt
was converted to the free acid by extraction with ethyl acetate and treatment
with acetic acid prior to mass spectral measurement. Again, the expected
molecular ion of diclazuril anion is 404.972 and the measured molecular
weight of 404.971 matched exactly to the expected weight. Isotopic peaks
arising from primarily from chlorine were also measured. Cluster of peaks
seen at 333.971 again corresponds to a fragment peak obtained after the loss of
two chlorine ions. An additional cluster of peaks at molecular weight 395.952
that was not seen in the mass spectrum of diclazuril starting material was seen
in the mass spectrum of diclazuril free acid obtained from the sodium salt.
This peak is thought to be either an unidentified fragment peak of the
molecular ion, peak arising from impurities or minor side product of the
titration reaction. Further analysis by HPLC is warrented to identify whether
this peak is a fragmentation product or an impurity.
pH stability of sodium salt of diclazuril
The manufacturer of diclazuril, JANSEEN Research Foundation, listed the
pKa of diclazuril to be 5.92 in its physico-chemical characteristics of diclazuril. It
can be expected that at pH's above the pKa of the compound (i.e. pH> 6),
aqueous solution of diclazuril would stay in solution. Preliminary studies were
conducted to determine the pH at which sodium salt would precipitate.
Sodium salt of diclazuril was dissolved in water. It went into solution
almost immediately. The pH of the aqueous solution was 12.4. To this solution.
1N HC1 was added dropwise while stirring and the pH at which the solution began
to turn cloudy was recorded. This pH was found to be 10.5. This would indicate
that the pKa of diclazuril is not 5.92 as indicated by JANSSEN but closer to 10.5.
Actually, a check of reference pKa's of organic compounds shows that imides
have a pKa in the range of 8.3-9.6.
The result of the pH stability study indicated that aqueous formulation of
sodium salt of diclazuril has to be formulated preferably at a higher pH close to 11
to ensure that the drug stays in solution. This will not cause a problem as there are
many drugs on the market that are formulated at higher pHs for exactly the same
reason.
Accordingly, the present invention provides a composition useful for the
treatment of a protozoal infection in man or in animals comprised of a water-
soluble form of a triazine-based anticoccidial including, but not limited to,
clazuril, diclazuril, toltrazuril, toltrazuril sulfone and sulfonotoltrazuril. In a
presently preferred embodiment of the invention, the water soluable triazine-based
anticoccidial is a sodium salt of clazuril, diclazuril, toltrazuril, toltrazuril sulfone,
sulfonotoltrazuril or a mixture thereof.
The preferred compositions can be utilized in methods of treatment of anti-
protozoal infections in man and in animals. For example, a presently preferred
treatment regimen for treatment of EPM comprises administering to a 1000 lb
horse a composition for intraveneus administration comprised of between about
50 mg to about 1,500 mg, but especially between about 250 mg and about 1000
mg and most preferably about 500 mg (about 1.1 mg/kg) of a water-soluble
sodium salt of diclazuril, toltrazuril, toltrazuril sulfone or sulfonotoltrazuril
dissolved in a suitable volume of water or stored in a freeze-dried preparation for
admixing with a suitable amount of sterile water for injection at the time of
utilization. Suitable amounts of water for the composition will vary from between
about 2 ml to about 30 ml per unit dose depending upon the choice of the anti-
protozoal agent and the parenteral route of administration.
According to the methods set forth herein for EPM treatment, the
composition can given once per day (SID) for a duration of between about 10 and
about 35 days but especially between about 20 and about 30 days and most
preferably about 28 days. Alternatively, a loading dose of the composition can be
given to achieve rapid critical plasma concentrations on day one of the regimen
followed by a maintenance dose (see, Example I above) for a shorter duration of
therapy, e.g., between about 15 and about 25 days.
It is also specifically contemplated that the water-soluble forms of the
triazine-based anticoccidials provided herein can be utilized in suitable oral
formulations for treatment and prevention of protozoal infections and infestations
in man and in animals. The solubility of the compositions provided herein greatly
enhance the oral bioavailability of the active anti-protozoal agent and accordingly
lessen the dosage requirement to roughly the equivalent of that of the parenteral
formulations. Given the teachings provided herein, the skilled artisan can
optimize the dosage requirements and the therapeutic regimen for a particular
formulation depending upon the condition being treated or prevented and the
species of animal.
One embodiment of the present invention provides a composition useful
for the treatment of a Cryptosporidium spp. infection especially in man or in
animals comprised of a water-soluble form of a triazine-based anticoccidial
including, but not limited to, clazuril, diclazuril, toltrazuril, toltrazuril sulfone or
sulfonotoltrazuril. In a presently preferred embodiment of the invention, the
water soluable triazine-based anticoccidial is a sodium salt of clazuril, diclazuril,
toltrazuril, toltrazuril sulfone, sulfonotoltrazuril or a mixture thereof and can be
used parenterally or orally in a therapeutic treatment regimen. It is also
contemplated that the above-described compositions comprised of a triazine-based
anticiccidial and a suitable solvent, e.g., DMSO or DMA, can be utilized
parenterally to treat Cryptosporidium spp. infection in man or in animals.
For example, a presently preferred treatment regimen for treatment of
Cryptosporidium spp. infection comprises administering to an approximately 200
Ib human subject from between about 10 mg to about 400 mg, but especially
between about 25 mg and about 300 mg and most preferably about 200 mg (about
1.1 mg/kg) of a water-soluble sodium salt of diclazuril, toltrazuril, toltrazuril
sulfone or sulfonotoltrazuril dissolved in a suitable volume of water or stored in a
freeze-dricd preparation for admixing with a suitable amount of sterile water for
injection at the time of utilization. Suitable amounts of water for the composition
will vary from between about 2 ml to about 10 ml per unit dose depending upon
the choice of the anti-protozoal agent and the route of route of administration. It
can certainly be appreciated that the oral formulations of the water-soluble salts of
these agents can be in a liquid, semi-solid or solid form as a pill tablet, elixir and
the like.
Current recommendations for treatment of EPM with pyrimethamine and a
sulfonamide are set forth in the above-cited articles by Dr. Clara Fenger (1995)
and Dr. Joe Bertone (1995 which are hereby incorporated by reference.
Accordingly, in yet another embodiment of the invention, the composition is
comprised of at least one anti-protozoal agent as set forth above and can also
comprise a reduced amount of a sulfonamide and/or pyrimethamine for the
parenteral, e.g., the intranasal formulations.
One skilled in the art can appreciate that depending upon the compound
which is selected as the therapeutic agent, the method of solubilization of the
compound for inclusion in the composition provided herein can vary and can be
readily ascertained based upon known chemical properties of the selected
compound, as found, e.g., in the material safety data sheets (MSDS) for the
particular compound or via known methods of synthesis etc.. In particular,
methods for solubilization of the active compound and formulation of
compositions that are specially adapted for intranasal administration are known as
set forth, e.g., in U.S. Patent Nos.: 4,284,648,4,428,883; 4,315,925 and
4,383,993, the contents of which are hereby incorporated by reference.
In view of the mixed results of the cases of EPM treated to date by the oral
route, it is very surprising that by utilizing a different route of administration (i.e.,
intranasal) and decreasing the dose, that one could achieve better results,
especially when using an anti-coccidial agent which has to exert its effect on the
organism in the horse. Furthermore, while the solubilization techniques suggested
above were known, it has not been heretofore suggested that such can be used for
solubilizing triazine-based anti-coccidial agents, such as diclazuril, toltrazuril, and
toltrazuril sulfone, in order to provide compositions for intranasal administration
The intranasal route allows for direct absorption of drug through the nasal mucosa
and directly across the blood brain barrier into the CSF without first having to
pass through the liver. This may produce the unexpectedly better result seen with
this route of administration, even with drastically lower unit dosages of drug.
For example, one embodiment of the invention utilizes a composition for
treatment of EPM adapted for intranasal administration which is comprised of
toltrazuril, toltrazuril sulfone or sulfonotoltrazuril in a therapeutically effective
amount in which the unit dose is less than the unit dose required for a
therapeutically amount of toltrazuril, toltrazuril sulfone or sulfonotoltrazuril as is
normally required for oral administration of either drug. In preferred
embodiments, the therapeutically effective amount of the compositions comprised
of toltrazuril, toitrazuril sulfone or sulfonotoltrazuril is between about 1/4th and
1/l00th but especially about 1/l0th of the therapeutically effective amount of
toltrazuril, toltrazuril sulfone or sulfonotoltrazuril that is required for oral
administration. Currently recommended oral dosage levels of toltrazuril,
toltrazuril sulfone or sulfonotoltrazuril are 5-10 mg/kg per unit dose administered
once daily orally such that a typical 500 kg horse would receive between about 2.5
to about 5 grams of active ingredient per day.
Thus, one presently preferred embodiment of the invention comprises a
composition comprised of toltrazuril, toltrazuril sulfone or sulfonotoltrazuril in
solution with N-methyl-glucamine and water. For instance, a typical example of
how to solubilize toltrazuril for use in the compositions contemplated by the
invention is to combine about 10 mg of toltrazuril with about 100 mg of N-methyl
glucamine and about 10 cc of water. One can appreciate given the known
properties of toltrazuril, toltrazuril sulfone or sulfonotoltrazuril that other solvents
can be utilized for use in preparation of the above compositions.
In one embodiment of the invention, the effective amount of toltrazuril,
toltrazuril sulfone or sulfonotoltrazuril per unit dose for intranasal administration
is between about 50mg and about l,500mg, but especially between about l00mg
and about 750mg. In one embodiment, the effective amount of toltrazuril,
toltrazuril sulfone or sulfonotoltrazurii per unit dose is about 500mg. Depending
upon the dosage required for either treatment or prevention of EPM (which can be
optimized utilizing methods known in the art) the appropriate amount of
toltrazuril or sulfonotoltrazurii can be solubilized for production of a unit dose or
the unit doses can be combined in a multiple treatment vial or container.
Likewise, another embodiment of the invention provides a composition
adapted for intranasal administration which is comprised of diclazuril in a
therapeutically effective amount in which the unit dose is less than the unit dose
for a therapeutically amount of diclazuril that is required for oral administration to
treat EPM. In preferred embodiments, the therapeutically effective amount of the
compositions comprised of diclazuril is between about l/4th and 1/100th but
especially about 1/10th of the therapeutically amount of diclazuril that is required
for oral administration.
A typical example of the solubilization of diclazuril for use in the
compositions contemplated by the invention is to combine about 10 mg of
diclazuril with about 20 mg of nicotinamide, about 300 mg of propylene glycol
and about 9-10 cc of water. It is contemplated that other solvents can be utilized
for preparation of the compositions comprising diclazuril. The skilled artisan can
select from among known solvents to fit a particular embodiment, see, e.g.
Janssen Pharmaceutica Safety Information for Diclazuril (R-64433) the contents
of which is incorporated herein by reference.
In one embodiment of the invention, the effective amount of diciazuril per
unit dose for intranasal administration is between about 50mg and about l,000mg,
but especially between about l00mg and about 750mg. In one embodiment, the
effective amount of diclazuril per unit dose is about 350mg. Depending upon the
dosage required for either treatment or prevention of EPM (which can be
optimized utilizing methods known in the art), the appropriate amount of
diclazuril can thus be solubilized for production of a unit dose or the unit doses
can be combined in a multiple treatment vial or container.
Accordingly, therefore, another embodiment of the invention provides a
composition adapted for intranasal administration which is comprised of
diclazuril, and DMSO in a therapeutically effective amount in which the unit dose
is less than the unit dose for a therapeutically amount of diclazuril that is required
for oral administration to treat EPM. In preferred embodiments, the
therapeutically effective amount of the compositions comprised of diclazuril and
DMSO is between about l/4th and 1/100th but especially about 1/10 th of the
therapeutically amount of diclazuril that is required for oral administration
One presently preferred embodiment of the invention, comprises a
composition adapted for intranasal administration comprising diclazuril
solubilized in DMSO. The diclazuril is placed into solution in the DMSO and can
be further formulated with other pharmaceutically acceptable carriers and
excipients for intranasal administration to fit a particular treatment regimen. A
typical unit dosage for administration is between about 50mg and about 750mg
but is especially between about l00mg and 500mg and preferably about 250mg.
In one example, 500 mg of diclazuril is dissolved in 10-15 cc of DMSO and can
be utilized for intra nasal administration. This same composition can also be
utilized for intravenous administration for treatment of EPM by methods provided
for herein.
Typically, the subject equid can be treated via intranasal administration of
the solution on a daily basis utilizing, e.g., a catheter and syringe to apply the
solution directly to the intranasal mucosa. Depending upon the disposition of the
animal, proper restraint should be utilized such as a nose twitch before initiation
of the procedure. After proper restraint of the animal, the catheter is advanced up
the animal's nostril to the level of the oropharnyx. Most of the solution is injected
through the catheter onto the nasal mucosa at the orophamyx with the remainder
being injected as the catheter is slowly withdrawn. For daily administration, as
with some of the methods of treatment provided herein, the nostrils may be
alternated so as to minimize irritation of the mucosa. The total volume of the
composition applied intranasally typically will not exceed 15-20cc per
administration and preferably does not exceed about l0cc per administration..
Additionally, as set forth in greater detail below, the above solution
comprised of diclazuril and DMSO can be further adapted for sustained release of
the diclazuril by any of a number of methods known in the art, including the use
of excipients and controlled release delivery systems comprised of, e.g., sucrose
acetete isobutyrate, methyl cellulose, or microparticles and the like. Frequency of
dosing and unit dosage amounts for the sustained compositions set forth herein
will vary, of course, depending upon the release characteristics of the delivery
system and the specific formulation. However, given the teachings of the
invention, optimization of dosage and the therapeutic regimen will be routine to
the skilled artisan.
Yet another embodiment of the invention comprises a composition for
treatment of EPM adapted for intranasal administration which is comprised of the
anti-protozoal nitazoxanide in a therapeutically effective amount in which the unit
dose is less than the unit dose required for a therapeutically effective amount of
-nitazoxanide (as set forth in the references cited above) as would normally be
required for the oral administration thereof. In preferred embodiments, the
therapeutically effective amount of the compositions comprised of nitazoxanide is
between about l/4th and 1/100th but especially about 1/10 th of the therapeutically
effective amount of nitazoxanide that would be required for oral administration.
It can be appreciated that other nitrothiazoles their derivatives, analogs,
isoraers, salts, and natural metabolites can also be utilized in the compositions for
treatment and prevention of EPM disclosed herein.
The dosage of nitazoxanide can vary from between about l00 mg to about
1,500 mg depending upon the specific formulation, but is especially between
about 250mg and about 1000mg for the intranasal formulations.
Another embodiment of the invention provides a composition adapted for
equine intranasal or other parenteral administration which is comprised of
pyrimethamine and at least one sulfonamide in a therapeutically effective amount
in which the unit dose is less than the unit dose for a therapeutically amount of the
same drug combination that is required for oral or other parenteral administration
to treat EPM. In preferred embodiments, the therapeutically effective amount of
the compositions comprised of pynmethamme and the sulfonamide is between
about l/4th and 1/l00th but especially about l/10th of the therapeuticaliy amount
of the same drug combination that is required for oral or other parenteral
administration. These compositions can, of course, contain more than one
sulfonamide in combination with pyrimethamine, as well as additional
pharmaceutically acceptable excipients and adjuvants.
Also contemplated are compositions adapted for parenteral (e.g.,
intramuscular, subcutaneous or intravenous) administration which are comprised
of at least one chemical agent one which has anti-protozoal activity, e.g., a triazine
based anticoccidial (a triazinedione or a triazinetrione e.g., diclazuril, toltrazuril
or sulfonotoltrazuril) or a nitrothiazole derivative, in a therapeuticaliy effective
amount in which the unit dose is less than the unit dose for a therapeuticaliy
effective amount of the chemical agent that is required for oral administration to
treat or prevent EPM. In preferred embodiments, the therapeuticaliy effective
amountofthe compositions comprised of the anti-protozoal is between about
l/2th and 1/100th but especially about 1/10th of the therapeuticaliy amount of
compound that is required for oral administration.
The invention also provides methods for treating and preventing EPM in
an equine, e.g., a horse, which comprise the intranasal administration of a
composition such as those provided by the invention. The optimization of the unit
dosage amounts and the treatment regimen can be accomplished utilizing methods
which are generally known to the skilled artisan.
The invention further provides methods for treating and preventing EPM
in an equine, e.g., a horse, which comprise the parenteral, i.e., subcutaneous,
intramuscular, intravenous, or transdermal administration of a composition such
as those provided by the invention. The optimization of the unit dosage amounts
and the treatment regimen can be accomplished utilizing methods which are
generally known to the skilled artisan.
In another embodiment of the invention, any of the antiprotozoal agents
disclosed herein but especially the triazine-based anticoccidial compounds or the
nitrothiazoles including, but not limited to diclazuril, toltrazuril or toltrazuril
sulfone, sulfonotoltrazuril and nitazoxanide can be placed in a composition
adapted for sustained release. The sustained release composition can comprise
any of a number of controlled delivery systems such as microparticles
(microspheres or microcapsules), gels, and the like for formulated for injection or
absorption. The sustained release compositions of the invention can be
administered by any oral or parenteral route including intramuscular,
subcutaneous, or intravenous injection. Likewise, the sustained release
composition can be adapted for transmucosal or transdermal delivery via a patch,
topical application, intranasal or intrauterine delivery and the like.
Materials useful for preparation of the microspheres or microcapsules
(microparticles) can include any biocompatable and preferably biodegradable
polymer, copolymer or blend. Suitable polymers include polyhydroxyl acids,
polyorthoesters, polylactones, polycarbonates, polyphosphazenes,
polysaccharides, proteins, polyanhydrides, copolymers thereof and blends thereof.
Suitable poly(hydroxy acids) include polyglycolic acid (PGA), polylactic acid
(PLA), and copolymers thereof. Preferably the microparticles include poly(D,L-
lactic acid) and /or poly(D, L-lactic-co-glycolic acid). Particles with degredation
and release times ranging from days to weeks or months can be designed and
fabricated, based on factors such as the materials used to prepare the
microparticles. Of course, the sustained release compositions contemplated can be
utilized in methods of treatment or for prevention of EPM.
The microparticles can be prepared using may method which does not
destroy the activity of the active compound. Microparticles can be prepared using
single and double emulsion solvent evaporation, spray drying, solvent extraction,
solvent evaporation, phase separation, simple and complex coacervation,
interfacial polymerization and other methods well known to those of ordinary skill
in the art.
Methods developed for making microspheres for drug delivery are
described in the literature, for example, as described in Doubrow, M., Ed,
Microcapsules and Nanoparticles in Medicine and Pharmacy, CRC Press, Boca
We Claim:
1. A method of making a medicament for treating or preventing a
protozoal infection in man or in animals, comprising:
combining a pharmaceutically acceptable carrier with a sodium salt
of a triazine-based anticoccidial agent, wherein the triazine-based
anticoccidial agent is selected from the group consisting of
clazuril, diclazuril, letrazuril, toltrazuril, toltrazuril sulfone,
sulfonotolrazuril, and mixture thereof, in proportios for therapeutic
dosage in the man or animal such that a therapeutically effective
amount of at least one said sodium salt of a triazine-based
anticoccidial agent is less than about 1/2 of therapeutically effective
amount of a corresponding non-salt of the iriazine-based
anticoccidial agent.
2. The method as claimed in claim 1 wherein the triazine-based
anticoccidial agent is a sodium salt of sulfonotoltrazuril or
toltrazuril sulfone.
3. The method as claimed in claim 1, wherein the triazine-based
anticoccidial agent is a sodium salt of diclazuril.
4. The method as claimed in claim 1 wherein the therapeutically
effective amount of the triazine-based anticoccidial agent is from
between about 0.01 mg/kg and about 20 mg/kg.
5. The method as claimed in claim 1 wherein the protozoal infection
is equine protozoal myeloencephalitis, the triazine-based
anticoccidial agent is diclazuril, the administration is oral and the
therapeutically effective amount is between about 0.01 mg/kg and
about 2.0 mg/kg.
6. The method as claimed in claim 8 wherein the therapeutically
effective amount is from between about 1 mg/kg and about 10
mg/kg.
7. The method as claimed in claim 1, wherein the protozoal infection
is human cryptosporidiosis in a human subject, the administration
is oral and the therapeutically effective amount is from between
about 0.01 mg and about mg/kg.
8. The method as claimed in claim 1, wherein the medicament is
formulated such that the therapeutically effective amount is less
than 1/3 the amount of a therapeutically effective amount of a
corresponding non-salt of the triazine-based anticoccidial agent.
9. The method as claimed in claim 1, wherein the medicament is
formulated such that the therapeutically effective amount is less
than 1/4 the amount of a therapeutically effective amount of a
corresponding non-salt of the triazine-based anticoccidial agent.
Raton, 1992. See also, US. Patent Nos. 5,407,609 and 5,654,008 the teachings of
which are incorporated herein by reference for methods of making microspheres
One specific example of a preferred embodiment of a controlled delivery
system of the invention is a composition comprised of any of the afore-mentioned
therapeutic agents, (including the any of the triazine-based anticoccidials and/or
nitazoxanide) and sucrose acetate isobutyrate (SAIB) as set forth is U.S. Patent
No. 5,747,058, the contents of which are incorporated herein by reference. The
compositions comprised of an anti-protozaol agent and SAIB, depending upon the
formulation, can be administered topically, (e.g., transdermally or
transmucosally), subcutaneously or intramuscularily.
Another specific example of a controlled release formulation embodied by
the invention is a composition comprised of any of the afore-mentioned
therapeutic agents, (including the any of the triazine-based antioccidials and/or
nitazoxanide) and methylcelulose (e.g., Methocel). It can be appreciated that
other, controlled release formulations can be used including other degradable or
non-degradable excipients, although degradable excipients are preferred. The
compositions comprised of an anti-protozaol agent and Methocel, depending upon
the formulation, can be administered topically, (e.g., transdermally or
transmucosally), subcutaneously or intramuscularily.
Furthermore, the invention provides the above compositions for use in
methods of treating and preventing another common problem of thoroughbred
racehorses, a condition called laryngeal hemiplegia, which has an unknown
etiology. While not wanted to be limited by theory, it is believed that laryngeal
hemiplegia may be caused by or exacerbated by EPM. Laryngeal hemiplegia is a
paralysis of the abductor muscles that open the arytenoid cartilages of the throat
due to what is believed to be recurrent laryngeal nerve damage. The arytenoid
cartilage cannot abduct to open the airway and causes the affected horse to make a
roaring" noise when exercised and he breathes heavily. Therefore, laryngeal
hemiplegia, and other potentially EPM-associated diseases and conditions can be
treated or prevented by the present invention.
Additional objects, advantages and other novel features of the invention
will be set forth in part in the description that follows and in part will become
apparent to those skilled in the art upon examination of the foregoing or may be
learned with the practice of the invention.
The foregoing description of a preferred embodiment of the invention has
been presented for purposes of illustration and description. It is not intended to be
exhaustive or to limit the invention to the precise form disclosed. Obvious
modifications or variations are possible in light of the above teachings. The
embodiment was chosen and described to provide the best illustration of the
principles of the invention and its practical application to thereby enable one of
ordinary skill in the art to utilize the invention in various embodiments and with
various modifications as are suited to the particular use contemplated. All such
modifications and variations are within the scope of the invention as determined
by the appended claims when interpreted in accordance with the breadth to which
they are fairly, legally and equitably entitled.
10. The method as claimed in claim 1, wherein the medicament is
formulated such that the therapeutically effective amount is less
than 1/10 the amount of a therapeutically effective amount of a
corresponding non-salt of the triazine-based anticoccidial agent.

A method of making a medicament for treating or preventing a protozoal
infection in man or in animals, comprising:
combining a pharmaceutically acceptable carrier with a sodium salt of a
triazine-based anticoccidial agent, wherein the triazine-based
anticoccidial agent is selected from the group consisting of clazuril,
diclazuril, letrazuril, toltrazuril, toltrazuril sulfone, sulfonotolrazuril, and
mixture thereof, in proportios for therapeutic dosage in the man or animal
such that a therapeutically effective amount of at least one said sodium
salt of a triazine-based anticoccidial agent is less than about 1/2 of
therapeutically effective amount of a corresponding non-salt of the
triazine-based anticoccidial agent.

Documents:

in-pct-2001-402-kol-abstract.pdf

in-pct-2001-402-kol-assignment.pdf

in-pct-2001-402-kol-claims.pdf

in-pct-2001-402-kol-correspondence.pdf

in-pct-2001-402-kol-description (complete).pdf

in-pct-2001-402-kol-examination report.pdf

in-pct-2001-402-kol-form 1.pdf

in-pct-2001-402-kol-form 18.pdf

in-pct-2001-402-kol-form 2.pdf

in-pct-2001-402-kol-form 26.pdf

in-pct-2001-402-kol-form 3.pdf

in-pct-2001-402-kol-form 5.pdf

in-pct-2001-402-kol-granted-abstract.pdf

in-pct-2001-402-kol-granted-assignment.pdf

in-pct-2001-402-kol-granted-claims.pdf

in-pct-2001-402-kol-granted-correspondence.pdf

in-pct-2001-402-kol-granted-description (complete).pdf

in-pct-2001-402-kol-granted-examination report.pdf

in-pct-2001-402-kol-granted-form 1.pdf

in-pct-2001-402-kol-granted-form 18.pdf

in-pct-2001-402-kol-granted-form 2.pdf

in-pct-2001-402-kol-granted-form 26.pdf

in-pct-2001-402-kol-granted-form 3.pdf

in-pct-2001-402-kol-granted-form 5.pdf

in-pct-2001-402-kol-granted-reply to examination report.pdf

in-pct-2001-402-kol-granted-specification.pdf

in-pct-2001-402-kol-granted-translated copy of priority document.pdf

in-pct-2001-402-kol-reply to examination report.pdf

in-pct-2001-402-kol-specification.pdf

in-pct-2001-402-kol-translated copy of priority document.pdf


Patent Number 235855
Indian Patent Application Number IN/PCT/2001/402/KOL
PG Journal Number 36/2009
Publication Date 04-Sep-2009
Grant Date 02-Sep-2009
Date of Filing 09-Apr-2001
Name of Patentee NEW ACE RESEARCH COMPANY
Applicant Address PAYNES DEPOT ROAD, VERSAILLES, KENTUCKY
Inventors:
# Inventor's Name Inventor's Address
1 HUNDLEY BRUCE PAYNES DEPOT ROAD, VARSAILLES, KY 40383
2 DELUCA PATRICK 3292 NANTUCKET ROAD, LEXINGTON, KY 40502
3 GEBREKIDAN SISAY 2148 LARKSBURG DRIVE APT 42C, LEXINGTON, KY 40504
4 MACLIN ROBERT 3144 WARRENWOOD WYND, LEXINGTON, KY 40502
5 MACLIN ROBERT 3144 WARRENWOOD WYND, LEXINGTON, KY 40502
6 HUNDLEY BRUCE PAYNES DEPOT ROAD, VARSAILLES, KY 40383
7 DELUCA PATRICK 3292 NANTUCKET ROAD, LEXINGTON, KY 40502
8 GEBREKIDAN SISAY 2148 LARKSBURG DRIVE APT 42C, LEXINGTON, KY 40504
PCT International Classification Number A61K 31/53
PCT International Application Number PCT/US1999/23566
PCT International Filing date 1999-10-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/103,543 1998-10-08 U.S.A.
2 60/112,175 1998-12-14 U.S.A.